285257 has 4 divisors (see below), whose sum is σ = 326016. Its totient is φ = 244500.

The previous prime is 285251. The next prime is 285281. The reversal of 285257 is 752582.

285257 is nontrivially palindromic in base 14.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 752582 = 2 ⋅376291.

It is a cyclic number.

It is not a de Polignac number, because 285257 - 2¹⁰ = 284233 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 285257.

It is not an unprimeable number, because it can be changed into a prime (285251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20369 + ... + 20382.

It is an arithmetic number, because the mean of its divisors is an integer number (81504).

2²⁸⁵²⁵⁷ is an apocalyptic number.

It is an amenable number.

285257 is a deficient number, since it is larger than the sum of its proper divisors (40759).

285257 is an equidigital number, since it uses as much as digits as its factorization.

285257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40758.

The product of its digits is 5600, while the sum is 29.

The square root of 285257 is about 534.0945609159. The cubic root of 285257 is about 65.8282187271.

The spelling of 285257 in words is "two hundred eighty-five thousand, two hundred fifty-seven".